As natural daylight recedes, artificial lights immediately come on everywhere—commercial signs, streetlights, headlights. When we reach our homes, more lights come on—porch lights, house lights, and television sets. We're clearly in denial that something hemispheric and profound is occurring in nature. If a divine being or angels or extraterrestrials were monitoring us, the most glaring global transformation they'd have witnessed in recent generations is the burgeoning, worldwide illumination of our nights.
The lightbulb, originally intended to extend the workday, has ignited the landscape and is burning out of control. Flying over the earth's populated areas at night, we see below us eerily illuminated enclaves of one species' hyperactivity. Everywhere else, life is slowing and quieting, in rhythm with the rotation of the earth.
Much of our use of light at night is gratuitous. Unnecessary for our welfare and safety, it primarily serves to import waking-world consciousness into the nighttime. Because 80 percent of sensory stimulation to the brain is visual, when the world darkens, we naturally go inward, relax, and rest. Our excessively illuminated evenings encourage excessive extraversion as our attention is drawn outward to activity. Most of my insomnia clients routinely remain active until bedtime. While the natural world around them is yielding to darkness, they turn on lamps, televisions, and computers, continuing the daytime hustle with projects, e-mail, errands, exercise, and entertainment.
But recent research suggests that merely being quietly awake in a darkened space produces beneficial effects on our bodies and minds. Just as light stimulates the release of serotonin, which energizes us, darkness encourages the production of melatonin, the key neurohormone in our nocturnal biology. There's mounting evidence that even minimal nighttime light exposure can damage our circadian rhythms and suppress the production of melatonin.
In our attempt to excise darkness from our lives, we've damaged the integrity and rhythm of our consciousness. With the loss of night, day loses its partner in the sacred dance of circadian cycles. Activity becomes dangerously devoid of rest. We lose our sense of the basic pulse of night and day—our awareness of life's natural rhythms. Ultimately, we lose our experience of the seamless continuity of consciousness, our sense of wholeness.
Damaged Sleep and Dreams